• Proceedings of the KIPE Conference
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• 2010.11a
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• pp.13-14
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• 2010

본 논문에서는 경계 모드(Critical Mode) 플라이백 타입의 DC-AC 인버터에 인터리빙을 적용한 디지털 제어를 제안한다. 연속모드(CCM)나 불연속모드(DCM)와 달리 경계 모드의 경우 주파수가 가변되기 때문에 인터리빙으로 구현하기는 상당히 까다로운 측면이 있다. 또한 아날로그 제어기로 구현에 한계를 지니기 때문에 보다 간편한 구현을 위해 디지털 제어IC을 이용하여 구현하는 방법에 대해 기술한다. 본문에서 200W급 플라이백 타입의 DC-AC 인버터에 경계모드 인터리빙을 방법을 적용한 후 실험으로 검증한다.

• Journal of Digital Convergence
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• v.15 no.10
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• pp.405-410
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• 2017

The purpose of this study is to suggest the guideline by analysing and categorizing the case of sharing economy service especially the co-working and co-living space based on Europe. I did some literature research followed with evaluation of theoretical backgrounds, present conditions. Also, Some case research based on the keyword of 4th industrial revolution and the space categorized by their characteristics. The result indicate that co-working and co-living space's features correlated with their characteristics of the location and birth of digital nomad life. Each space has their flat-form community for the needs of closer cooperation between the user and user in common. I expect this study will become a good resource for upgrading domestic co-working and co-living space and also I hope that this study can guide follow-up next studies.

• Journal of Digital Convergence
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• v.18 no.8
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• pp.37-48
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• 2020

This study aimed at understanding trends of living lab studies and deriving implications for directions of the studies by utilizing text mining. The study included network analysis and topic modelling based on keywords and abstracts from total 166 thesis published between 2011 and November 2019. Centrality analysis showed that living lab studies had been conducted focusing on keywords like innovation, society, technology, development, user and so on. From the topic modelling, 5 topics such as "regional innovation and user support", "social policy program of government", "smart city platform building", "technology innovation model of company" and "participation in system transformation" were extracted. Since the foundation of KNoLL in 2017, the diversification of living lab study subjects has been made. Quantitative analysis using text mining provides useful results for development of living lab studies.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.31 no.5C
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• pp.497-502
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• 2006

In this paper, we propose a digital image encryption method using adaptive interleaving and multiple random shuffling table to improve the existing encryption methods which use a fixed random shuffling table. In order to withstand the plaintext attack, at first, we propose a interleaving method that is adaptive to the local feature of image. Secondly, using the proposed interleaving only shuffling method and multiple shuffling method that is combined interleaving with existing random shuffling method, we encrypted image by shuffled the DPCM processed $8^*8$ blocks. Experimental results show that, the proposed algorithm is very robust to plaintext attack and there is no overhead bit.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.38 no.10
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• pp.721-727
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• 2001

In this paper, we propose a two-dimensional interleaving structure of holographic digital data storage. In this storage, many of the digital binary data are recorded, retrieved and processed in a two-dimensional data image (1000$\times$1000 bits). Therefore, burst errors in this digital device also have two-dimensional characteristics and it is required to use effective two-dimensional interleaving to overcome them. Bits of every code word should be distributed in an equilateral triangular lattice structure when they are scattered considering the random shape and occurrence of burst errors. We deal with factors and algorithm to construct this interleaving structure of equilateral triangular lattice.

• The Journal of the Acoustical Society of Korea
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• v.38 no.2
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• pp.207-213
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• 2019

In this paper, we evaluate the communication performance of convolutional code with block interleaving in a frequency-selective channel. Block interleaving is a technique for spreading and rearranging digital data streams. A block interleaving technique is applied to improve the performance by dispersing the concentration of burst errors in a frequency-selective channel. As a result of evaluating the performance of the convolutional code with block interleaving in the water tank experiment, There was no difference in the performance of convolutional codes using block interleaving in a frequency-selective channel. However, in the frequency-selective channel, the convolutional code with block interleaving has a gain of 2dB, and it is confirmed that the underwater acoustic communication performance is improved.

• Journal of Digital Convergence
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• v.19 no.10
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• pp.15-20
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• 2021

The crisis of university must be overcome by emphasizing the acquisition and use of knowledge for students to participate in and solve contemporary and diverse social/regional problems through educational method innovation. University classes should be a way of contributing to solving human problems, the UN's Sustainable Development Goals(SDGs) and various issues in the community. This study focused on project-based learning to cultivate socially engaged and problem-solving talents. In addition, a problem definition toolkit model was produced and tested to improve problem solving ability. Through follow-up research, I plan to develop a performance measurement model corresponding to the field application-improvement-feedback of Living Lab project classes, and suggest a method that universities can easily apply to the existing curriculum.

• The Journal of the Acoustical Society of Korea
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• v.24 no.4
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• pp.202-209
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• 2005

The rapid development of digital media and communication network urgently brings about the need of data certification technology to protect IPR (Intellectual property right). This paper proposed a new watermarking method for embedding owner's audio signal. Because this method uses an audio signal as a watermark to be embedded, it is very useful to claim the ownership aurally. And it has the advantage of restoring audio signal modified and especially removed by image removing attacks by applying our LBX(Linear Bit-expansion) interleaving. Three basic stages of our watermarking include: 1) Encode . analogue owner's audio signal by PCM and create new digital audio watermark, 2) Interleave an audio watermark by our LBX; and 3) Embed the interleaved audio watermark in the low frequency band on DTn (Discrete Haar Wavelet Transform) of image. The experimental results prove that this method is resistant to lossy JPEG compression as standard image compression and especially to cropping and rotation which remove a part of Image.

• Journal of Digital Convergence
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• v.18 no.4
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• pp.121-127
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• 2020

Innovation in local industries and the development of public services require, among other things, shared growth with the concept of regional co-prosperity. Regional co-prosperity is essentially aimed at bridging regional balance or regional gaps, which means a relationship that can achieve shared growth through complementary cooperation. In this study, cases using living labs were drawn based on the current status of industry-academic cooperation at the level of regional innovation and its policy implications were sought. Local governments are making various attempts to solve regional problems and enhance the linkage effect of securing mutual competitiveness through co-prosperity cooperation autonomously. In particular, an effective approach has been continued by activating the Living Lab Network, a problem-solving mechanism, focusing on pending regional issues. Above all, one of the strategies for regional development should be linked to the establishment of a cooperative system for win-win cooperation and policy means to support it. The activation of cooperative programs with local universities, companies and local governments and the case of problem-solving using living labs. Therefore, it suggested that active participation by various stakeholders and a cooperative governance model were needed to enable Living Lab.

• The Transactions of the Korea Information Processing Society
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• v.7 no.10
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• pp.3290-3299
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• 2000

Digital watermarking has similar concepts with channel coding thechnique for transferring data with minimizing error in noise environment, since it should be robust to various kinds of data manipulation for protecting copyrights of multimedia data. This paper proposes a digital watermarking technique which is robust to various kinds of data manipulation. Intellectual property rights information is encoded using a convolutional code, and block-interleaving technique is applied to prevent successive loss of encoded data. Encoded intelloctual property rithts informationis embedded using spread spectrum technique which is robust to cata manipulation. In order to reconstruct intellectual property rights information, watermark signalis detected by covariance between watermarked image and pseudo rando noise sequence which is used to einbed watermark. Embedded intellectual property rights information is obtaned by de-interleaving and cecoding previously detected wtermark signal. Experimental results show that block interleaving watermarking technique can detect embedded intellectial property right informationmore correctly against to attacks like Gaussian noise additon, filtering, and JPEG compression than general spread spectrum technique in the same PSNR.